In accordance with the requirements of citation databases, proper citation of publications appearing in our Quarterly should include the full name of the journal in Polish and English without Polish diacritical marks, i.e. "Eksploatacja i Niezawodnosc – Maintenance and Reliability".

Task „Implementation of procedures ensuring the originality of scientific papers published in the quarterly „Eksploatacja i Niezawodność – Maintenance and Reliability” financed under contract 532/P-DUN/2018 from the funds of the Minister of Science and Higher Education for science dissemination activities.

Exhaust opacity in a diesel engine powered with animal fats

The diversification of sources of energy has been recognised as one of the actions preventing the negative effects of human activity on the environment. In order to do so it is necessary to solve the problems related with the replacement of fossil fuels with biofuels, including the increase in the prices of food products caused by the dynamic development of biofuels made from plants. Therefore, the aim of the study was to make an experiment assessing the technical possibilities to replace diesel fuel with rendered animal fats. As results from the initial study, the kinematic viscosity of animal fats at a temperature of 120°C is comparable to that of diesel at 40°C. Apart from that, the diesel engine powered with animal fats emitted 70% less particulates in exhaust than the engine powered with a diesel fuel.

Power performance of farm tractor in field operations

Many studies have examined the effects of agriculture tractor engine energy performance. This paper presents an evaluation method of such engine actual power use during plowing operations. It includes results of a comparative study of power performance of a 230 kW tractor model John Deere 8330 subject to soil plowing operations as a function of field size: A (26 ha), B (12.74 ha), C (3.22 ha). Statistical data clustering, a relatively novel approach in studies on actual utilization of engine power, was used. A positive correlation was observed between field size and the active state of the engine: 75.2% field A; 68.8% field B; 46.8% field C. The actual power utilization of agriculture tractor engine as a function of field size was 0.62, 0.58 and 0.39 respectively for the three fields used in this study. With this evaluation approach, performance indexes of operational power performance in various conditions were obtained for possible use in optimization of plowing operations.